The increasing possibilities for treating and correcting genetic disorders in human patients by approaches ranging from gene product replacement to gene transfer have created an increasing need for animal models in which to investigate pathogenetic mechanisms and approaches to therapy. The large reservoir of naturally-occurring counterparts of human genetic disease in animals has not been adequately utilized, in part because of the lack of accessible laboratories providing the special studies needed to identify and define genetic disorders in animals. The objective of this project is to establish a national Referral Center for the identification, characterization, evaluation, and dissemination of animal models of human genetic disease. The Center will provide consultation and laboratory studies of animals with signs suggestive of a useful new counterpart of human genetic disease. Laboratory studies include cytogenetics (routine and banded karyotyping), screening for inborn errors of metabolism, identification of abnormal metabolites, and special and routine pathologic studies of biopsies and postmortem specimens. Family studies and breeding experiments will be used to define modes of inheritance. Evaluation of breed aggregations and inheritance patterns will be assisted by computer-based pedigree analysis. Promising models will be made available to the general biomedical community, and germ plasm preserved by freezing and storing semen.